1. Field of the Invention
The present invention relates to methods for querying point of interest (POI) information in personal navigation devices (PNDs), and more particularly, to a method utilized for querying and displaying POI category and POI item information in a PND.
2. Description of the Prior Art
Personal navigation devices (PNDs) utilize navigation satellite signals, such as Global Positioning System (GPS) satellite signals, to determine their immediate location at any point on the Earth with satellite coverage. When location information is further combined with street maps, navigation is possible, such that, even if a user were to deviate from their planned route, the personal navigation device may use the immediate location to find the user's current location on the street map, and rechart a course to navigate safely to the user's intended destination.
As the PNDs become more developed, many additional features are included, such as color displays, voice prompts, and point of interest (POI) locators. These advances are brought about by improvements in liquid crystal display (LCD) technology, touch screen technology, storage media, processing speed and efficiency, as well as database development and population. Another important addition to the PND is a network interface module, whether that be in the form of a Bluetooth transceiver connected to a GPRS modem, an integrated 802.11-type transceiver, a 3G transceiver, or a WiMax transceiver. The PND having the network interface module may be called a “connected PND”, and is able to access online databases containing information about POIs that can be cross-referenced to the user's immediate position, or a position along the user's current route to their intended destination.
Please refer to FIG. 1, which is a diagram illustrating a POI database query method according to the prior art, and FIG. 2, which is a diagram illustrating a search interface displaying search results from FIG. 1 based on a query. As shown in FIG. 1, a PND 110 accesses a POI repository 130 through an intermediary server 120. The POI repository 130 has a categorized list of a large number of POIs, and the intermediary server 120 has a list of all categories of POIs contained in the POI repository 130. Two methods may be employed for accessing the POI repository 130. In the first method, which may be termed “search by item,” the PND 110 sends the query to the intermediary server 120. The intermediary server 120 may have a list of a plurality of root categories, such as “Restaurants” and “Museums,” and respective subcategories of the root categories, such as “Fast Food,” “Italian,” and “Chinese” subcategories for the Restaurants root category, and “Art” and “History” subcategories for the Museums root category. The intermediary server 120 submits the query directly to the POI repository 130, which returns POI information as search results back to the PND 110 through the intermediary server 120. In the second method, which may be termed “browse by category,” the PND 110 browses the plurality of root categories and respective subcategories on the intermediary server 120, and, upon reaching a lowest level subcategory, e.g. the Chinese subcategory under the Restaurants root category, the intermediary server 120 retrieves a list of POIs cross-referenced by location of all POIs in the Chinese subcategory from the POI repository 130.
As shown in FIG. 2, when the user enters a query for “Chinese” in a POI Locator interface 220 run on the PND 110, the intermediary server 120 passes the query on to the POI repository 130, and the POI repository 130 responds with a list of POIs containing the word “Chinese” located near the current position of the PND 110. As shown, the search results include “Chinese Wok” and “Han's Chinese”.
Although the method of the prior art is capable of delivering POI information to the user of the PND through searching or browsing, the prior art method can lead to some problems. First, the user may be uncertain as to what string to use to find the items they are looking for. Second, the user cannot see the whole category/subcategory tree, and therefore does not necessarily know which root category to start with, or whether there is a category for the item they are looking for. The user has to make a choice between the two modes and may be uncertain as to whether browsing will be more fruitful than searching. Also, it is often the case that an item can be found in multiple categories, but this is unclear when making the decision to browse. Another problem is that the search may span multiple databases, some of which may only support text search or support incompatible categories. And finally, where the device providing the search UI has only a small screen, the user is not able to see all categories at once.